The new system has already crashed twice since going live less than a month ago, forcing operators to take critical caller information using pen and paper and then pass that information off to runners who carry it to dispatchers.

“The 911 operators are overwhelmed, they have an incredibly challenging job,” Steve Cassidy, president of the Uniformed Firefighters Association, said outside City Hall on Friday. “The change that was made in 2009 did not help them, did not help the public. The simple answer is go back to the old system.”

The EMS union blames problems with the new system for an eight-minute delay in dispatching help to the scene of a fatal car crash on June 4 on the Upper West Side.

Ariel Russo, 4, and her grandmother were hit by an SUV when it jumped the curb on West 97th Street and Amsterdam Avenue.

Officials said the 911 call came in at 8:15:38. It reached fire EMS at 8:15:40, but an ambulance wasn’t dispatched until four minutes later at 8:19:42. It took a total of eight minutes for an ambulance to reach the scene.

The little girl died of her injuries at St. Luke’s Hospital. Her grandmother suffered a broken back and leg.

Ariel’s family, who testified at the hearings on Friday, has blamed her death on the 911 call. They said it delayed a response from an ambulance and is now suing the city.

“The lifeline we all count on did not arrive,” a grieving Sofia Russo said during her testimony, “Please let’s not let another person wait too long for medical help.”

Fire Commissioner Sal Cassano admitted there are glitches in the system, but blamed dispatcher error for the delay in the June 4 incident.

“Somebody made a mistake that was handling that call and we’re looking into it. We’ll find out what happened,” Cassano said after the accident.

The experienced EMS dispatcher was going on break and didn’t see the call, but the dispatcher’s replacement acted immediately, Cassano said.

Other delays have also been reported. There was a delay of 2 hours and 28 minutes for a car accident on 89th Street and 103rd Avenue and a delay of 1 hour and four minutes for a crash on 94th Street and Astoria Boulevard.

Cassano claimed the gaps in time are caused by cops responding to calls first and then calling EMS.

But City Council member Peter Vallone, Jr. called the system “seven years late and $1 billion over budget.”

“You would think that when it got here, it would work — but it doesn’t,” he said. “It’s way too of an important issue, this life or death issue, for us to be having a ‘he said, she said’ as to why it doesn’t work.”

Police Commissioner Ray Kelly stands behind the new system and said the bugs are being worked out.

“I’m told by the experts that you’re going to have kinds of bumps or hiccups at the beginning of installing a major system like this,” Kelly said.

Deputy Mayor Cas Holloway also defended the system, calling it money well-spent for the safety of New Yorkers. Holloway blamed Russo’s death on “reckless criminal behavior” and said that the new system is more stable than ever before.

Dispatchers disagreed and said that if human error was the problem it would mean that the Russo call was left flashing on 24 screens with at least 30 employees failing to act on it, CBS 2’s Dave Carlin reported.

“Response times to life saving emergencies have been dropping steadily for the last several years and have never been better,” he said. “Many of the false or misleading claims you’ll hear have been misreported in the media but are being used as a scare tactic to protect union jobs even if that means slow, ineffective systems in place.”

Holloway also promised to change the way the 911 response times are calculated, saying that the clock would begin ticking as soon as a call is placed.

The council committees on public safety and on fire and criminal justice services are holding the hearings.

The company that developed the new 911 apparatus has had similar problems with emergency dispatch systems it designed in Nassau County and San Jose, Calif.